The Google Shopping Content Objective-C Library by Google can access API data to sell products on Google, list ads, drive traffic, and increase sales. Developers can interact with the JSON API, working with iOS 3+ and Mac OS X 10.5+. Available introduction and example applications.
Those worried about whether the internet will kill the local retailers have either a positive sign or another reason to worry. Location-based shopping company Retailigence has announced its first round of developer applications. The apps use the Retailigence API to look for products in stock at local stores, by either keyword or barcode. Brick and mortar retailers have long feared similar technology, which could be used to find a better deal online, where there are not the same real estate costs. Retailigence hope to flip that for local retailers, making it easy for consumers to shop locally.
So far, Paul Hunkin's bot has bought him two sets of camera batteries, a gift bag, a USB extension cord, a 1955 stamped envelope and a smattering of other items. Hunkin, you see, decided to bring an XKCD cartoon to life by programming a bot that automatically purchases cheap items using a New Zealand auction site's Trade Me API... because packages are exciting.